Hi, Allen!
In fact, it is possible to do it now without DST, using unboxed closures only:
#![feature(unboxed_closures, unboxed_closure_sugar)]
fn make_adder(x: int) -> Box<|&: int| -> int> {
box |&: y: int| x + y
}
fn main() {
let f = make_adder(3);
println!("{}", f.call((4i,)));
}
Test it here: http://is.gd/mCJ6Dh
This code employs the idea that unboxed closure is just an instance of
some anonymous struct implementing one of Fn* traits, so we can just
return a boxed trait object representing the closure. The call syntax
is ugly, however, but this should change in the nearest future (though
explicit dereferencing, like (*f)(x), will likely be needed anyway).
2014-09-10 0:39 GMT+04:00 Allen Welkie <allen.wel...@gmail.com>:
> In this stackoverflow question:
>
> http://stackoverflow.com/questions/21130272/return-a-closure-from-a-function
>
> Chris Morgan mentions the possibility of adding closures with owned
> environments with the DST implementation. Is this being done with the
> current DST effort? If not, are there plans to add it?
>
> _______________________________________________
> Rust-dev mailing list
> Rust-dev@mozilla.org
> https://mail.mozilla.org/listinfo/rust-dev
>
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